these businesses grow. >> mitt romney's message is to get rid of the wind production tax credit. well, that's big here because we've got t.p.i. and trinity both producing wind turbines and wind towers, and that's a critical factor for us to keep those plants moving past 2013. >> reporter: o. kay henderson says these single issue voters add up quickly in such a small state. >> if iowa does again come down to a few thousand votes, these sort of narrow cast issues can have a huge effect. and so that is why you see the obama campaign pushing this so hard, because the wind energy industry has about 7,000 or 8,000 workers in iowa. >> reporter: then there is the fight in plain sight-- the >> romney would jeopardize thousands of jobs and knock the wind out of iowa's economy. >> a prairie fire of debt is sweeping across the nation. >> reporter: the negative ads are on >> reporter: the negative ads on almost every channel, every night. >> i mean, it's almost-- the ads border on being vulgar. >> reporter: steve bump has run a fireplace business in the des moines suburbs for 38 years, he kno